CORK, Ireland—Consuming probiotic-rich foods such as yogurt and dairy drinks have been shown to improve digestive health, but new research published in the journal Proceedings of the National Academy of Sciences reveals probiotics may benefit brain health by significantly alleviating stress, anxiety and depression.
Researchers at the University College Cork examined the effect of feeding a lactic bacteria named Lactobacillus rhamnosus JB-1 in rats. They found rats that consumed the gut bacteria displayed significantly less behavior linked with stress, anxiety and depression compared to mice who did not consume the probiotic. Bacteria-fed mice also had significantly lower levels of the stress hormone corticosterone in response to stressful situations.
The researchers also showed that regular feeding with the Lactobacillus strain caused changes in the expression of receptors for the neurotransmitter GABA in the mouse brain, which is the first time that it has been demonstrated that potential probiotics have a direct effect on brain chemistry in normal situations. The authors also established that the vagus nerve is the main relay between the microbiome (bacteria in the gut) and the brain. This three way communication system is known as the microbiome-gut-brain axis and these findings highlight the important role of bacteria in the communication between the gut and the brain, and suggest that certain probiotic organisms may prove to be useful adjunct therapies in stress-related psychiatric disorders.
The findings support a recent study conducted at Texas Tech University Health Sciences Center that concluded improving probiotic microflora in the intestines may be an important key to treating mental health conditions. The researchers found probiotics play a role in producing, absorbing, and transporting neurochemicals, such as serotonin, dopamine and nerve growth factor, which are essential for healthy brain and nerve function.